Among the conventionally-known working machines are ones in which towing wheels are mounted on a bottom section of the body of the working machine (i.e., working machine body) and a pair of handle bars, constituting a towing handle, are pivotably mounted on a top section of the working machine body, an example of which is disclosed in Japanese Patent No. 4226404 (hereinafter referred to as “patent literature”). The pair of handle bars is pivotable between stored position where the handle is stored in the machine body and a deployed position where the handle is deployed from the machine body. The machine body is towable by a user or human operator pulling the handle bars retained in the deployed position. Namely, the working machine disclosed in the patent literature has portability such that it can be moved by being towed by a user or human operator using the handle.
The working machine disclosed in the patent literature also includes a handle lock structure for locking the pair of handle bars in the deployed position, and the handle lock structure includes a pair of lock cancellation levers provided on respective ones of the handle bars. By operating the individual lock cancellation levers, the human operator can cancel a locked state of the pair of handle bars and thereby retract the pair of handle bars from the deployed position to the stored position.
However, when the pair of handle bars (towing handle) is to be retracted from the deployed position to the stored position, the handle lock structure shown in the patent literature, there is a need for the human operator to first operate the pair of lock cancellation levers and then move the pair of handle bars to the stored position. Thus, operation for retracting the pair of handle bars to the stored position would require extra labor. Particularly, where the handle and handle lock structure is employed in a compact, portable working machine having excellent portability, it is necessary to stabilize the working machine when operating the lock cancellation levers; thus, the operation for retracting the handle to the stored position would require further labor.